1. Field of the Invention
This invention relates to loose-leaf file folders and has particular reference to a system for hingedly retaining loose leaves or sheets in such folders.
2. Description of the Prior Art
Conventional loose-leaf file retainers generally comprise a metallic U-shaped member having deformable tabs which are inserted through perforations in a file folder cover or flap and through perforations in a stack of loose sheets there to be bent over to retain the sheets in place. Alternatively, the portion of the U-shaped member between the deformable tabs may be fixed to the inside face of a file folder and the assembly sold as a ready-to-use item. Optionally, a locking cross member may be added on top of the stack of loose sheets to retain the deformable tabs in place. In order to insert or remove a selected sheet from an interior position in the stack, all the sheets in the stack above that position must be removed from the tabs and replaced afterward.
Although such conventional sheet retainers are generally satisfactory, the process of removing a portion of a stack, particularly if it is quite thick, and then replacing it by guiding the relatively flexible retainer tabs through sometimes misaligned perforations is somewhat tedious and can result in some of the sheets being misplaced or replaced out of order. Additionally, in order to simply photo copy a sheet within the middle of a large stack requires either a removal and replacement process as described. Also, such retainers generally clamp the sheets together along one edge so that those sheets above a selected one in a stack cannot be laid back flat, but must be bent or curled back upon themselves. This again presents an inconvenience when attempting to copy and makes it awkward to read a sheet within the stack, especially when handling a file containing a relatively thick stack of sheets.
In U.S. Pat. No. 4,932,804 to Richards, a loose-leaf retainer for file folders is shown. Flexible, plastic retainer strips extend through guide channels in anchor elements secured to the cover of a file folder. The flexible retainer strips have connecting ends to form a closed loop and contain a stack of loose sheets through perforated holes in the sheets. The connection at the ends of the retainer strips comprise a generally bulbous head on one end providing a friction fit into a mating socket on the other end. Sockets are also formed between the ends to adjust the loops to fit the stack of sheets. The full loops can rotate in the paper holes to permit removal or insertion of a sheet in any location in the stack without removing other sheets. Also, the loops permit a portion of the stack to be rotated 180.degree. and lie flat. However, the sheets cannot be rotated 360.degree. from one side of the file folder to the other to enable a sheet to lie flat on a photocopy machine because the anchor elements fixed on the first side of the file folder interfere.
The present invention provides several improvements over prior loose-leaf retainer systems.